SHUTDOWN(8) NetBSD System Manager's Manual SHUTDOWN(8)
NAMEshutdown -- close down the system at a given time
SYNOPSISshutdown [-bbootstr] [-Ddfhknpr] time [message ... | -]
DESCRIPTIONshutdown provides an automated shutdown procedure for super-users to
nicely notify users when the system is shutting down, saving them from
system administrators, hackers, and gurus, who would otherwise not bother
with such niceties.
Available friendlinesses:
-bbootstr
The given bootstr is passed to reboot(8) for the benefit of
those systems that can pass boot arguments to the firmware.
Currently, this only affects sun3 and sparc machines.
-d shutdown will pass the -d flag to reboot(8) or halt(8) to
request a kernel core dump. If neither the -h or -r flags are
specified, then -d also implies -r.
-f shutdown arranges, in the manner of fastboot(8), for the file
systems not to be checked on reboot.
-h The system is halted at the specified time, using halt(8).
-k Kick everybody off. The -k option does not actually halt the
system, but leaves the system multi-user with logins disabled
(for all but super-user).
-n Prevent the normal sync(2) before stopping.
-p The system is powered down at the specified time, using halt(8).
If the powerdown fails, or the system does not support software
powerdown, the system will simply halt instead.
-r The system is rebooted at the specified time, using reboot(8).
-D Prevents shutdown from detaching from the tty with fork(2)/
exit(3).
time Time is the time at which shutdown will bring the system down
and may be the word now or a future time in one of two formats:
+number, or [[[[[cc]yy]mm]dd]hh]mm, where the century, year,
month, day, and hour may be defaulted to the current system val-
ues. The first form brings the system down number minutes from
the current time; the second brings the system down at the abso-
lute time specified. If the century is not specified, it
defaults to 1900 for years between 69 and 99, or 2000 for years
between 0 and 68. A leading zero in the ``yy'' value is not
optional.
message ...
Any other arguments comprise the warning message that is broad-
cast to users currently logged into the system.
- If - is supplied as the only argument after the time, the warn-
ing message is read from the standard input.
BEHAVIOR
At intervals, becoming more frequent as apocalypse approaches and start-
ing at ten hours before shutdown, warning messages are displayed on the
terminals of all users logged in. Five minutes before shutdown, or imme-
diately if shutdown is in less than 5 minutes, logins are disabled by
creating /etc/nologin and copying the warning message there. If this
file exists when a user attempts to log in, login(1) prints its contents
and exits. The file is removed just before shutdown exits.
At shutdown time, a message is written in the system log containing the
time of shutdown, who initiated the shutdown, and the reason. Next a
message is printed announcing the start of the system shutdown hooks.
Then the shutdown hooks in /etc/rc.shutdown are run, and a message is
printed indicating that they have completed. After a short delay,
shutdown runs halt(8) or reboot(8), or sends a terminate signal to
init(8) to bring the system down to single-user mode, depending on the
choice of options.
The time of the shutdown and the warning message are placed in
/etc/nologin and should be used to tell the users why the system is going
down, when it will be back up, and to share any other pertinent informa-
tion.
FILES
/etc/nologin tells login(1) not to let anyone log in
/fastboot tells rc(8) not to run fsck(8) when rebooting
/etc/rc.shutdown System shutdown commands
SEE ALSOlogin(1), wall(1), fastboot(8), halt(8), init(8), poweroff(8), reboot(8),
rescue(8)BACKWARD COMPATIBILITY
The hours and minutes in the second time format may be separated by a
colon (``:'') for backward compatibility.
HISTORY
The shutdown command appeared in 4.0BSD.
NetBSD 5.1 October 21, 2008 NetBSD 5.1

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